package nl.rug.search.odr.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import javax.ejb.EJB;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import nl.rug.search.odr.RequestParameter;
import nl.rug.search.odr.entities.Project;
import nl.rug.search.odr.entities.ProjectMember;
import nl.rug.search.odr.export.TeXExport;
import nl.rug.search.odr.project.ProjectLocal;
import nl.rug.search.odr.util.AuthenticationUtil;

/**
 *
 * @author Ben Ripkens <bripkens.dev@gmail.com>
 */
@WebServlet(name = "TeXExportServlet", urlPatterns = {"/texExport"})
public class TeXExportServlet extends HttpServlet {

    @EJB
    private ProjectLocal pl;

    public static final int ERROR_CODE = 303;
    
    /** 
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        if (!AuthenticationUtil.isAuthenticated(request.getSession())) {
            response.sendError(ERROR_CODE);
            return;
        }

        long userId = AuthenticationUtil.getUserId(request.getSession());

        long projectId;

        try {
            projectId = Long.parseLong(request.getParameter(RequestParameter.ID));
        } catch (NumberFormatException ex) {
            response.sendError(ERROR_CODE);
            return;
        }

        Project p = pl.getById(projectId);

        if (p == null) {
            response.sendError(ERROR_CODE);
            return;
        }

        boolean isMember = false;

        for (ProjectMember pm : p.getMembers()) {
            if (pm.getPerson().getId().equals(userId)) {
                isMember = true;
                break;
            }
        }

        if (!isMember) {
            // TODO: Inform the user that he is not a member of the project? This only happens when the user is abusing the system
            response.sendError(ERROR_CODE);
            return;
        }
        
        response.setContentType("application/octet-stream");
        response.setHeader("Content-disposition", "attachment; filename=texExport.zip");
        
        new TeXExport(response.getOutputStream(), p).export();
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
